34 
Rowland M. Shelley 
Receptacle large, convoluted, cupped around ventral edges of valves; 
valves elongate, oriented subdorsoventrally in body; operculum minute, 
located under dorsal end of valves. 
Range. —Along Savannah River in piedmont South Carolina from 
the vicinity of Clemson to McCormick. 
Species: One 
Relationships. — Brevigonus is most closely related to Cleptoria. The 
acropodite of the latter also is rather short, and this plus the common 
wedgeshaped prefemoral processes and the massive nature of the 
gonopods indicate close affinity between the two genera. I believe that 
Brevigonus evolved more recently than Cleptoria and that it may be 
derived from that genus. 
3 
Figs. 3-6. B. shelfordi holotype. 3, sternal process of segment 4, caudal view. 
4, left gonopod, medial view, setation omitted. 5, same, lateral view. 6, topotype, 
distal portion of acropodite, medial view. Scale line = 1.00 mm for Figs. 4-5, 
0.67 mm for Figs. 3 and 6. 
